Bridging plug



April 6, 1937. l w. T. WELLS ET Al.

BRIDGrING PLUG Filed April 20, 1935 3 `Sheets-Sheet 1 62# SP5/vete w` T. WELLS ET AL 7 BRIDGING PLUG Filed April 2o, 1955 3 Sheets-Sheet 2 April 6, 1937.

lllllltlll mu-ab 5, 1937. ,w. T. WELLS E1- Al. 2,076,307

BRIDGING PLUG Patented Apr. 6, 1937 BRIDGING PLUG Walter T. Wells and Charles H. Barnes, Glendale,

and Lloyd Spencer, Los Angeles, Calif., assignors to The Technicraft Engineering Corp., Los Angeles, Calif., a corporation of California Application April Izo, 1935, serial No. 17,466

1s claims. (c1. 16e- 13) Our invention relates to bridging plugs; that is, plugs or packers which are placed in oil wells or the like for the purpose of sealing or plugging od and abandoning a lower section of a well bore. Such plugs are employed, for example, whenever a lower zone has ceased to be productive or for any other reason it is desirable to produce from an upper zone. It is customary to position a.v bridging plug, then to cement on top of the plug; however, a difiiculty has been experienced in securing the plug and maintaining the plug in the desired place during the cementing operation. The plug is sometimes driven ,down by the cementngbailer, and

other times the formation pressure below builds up sufficiently to raise the plug as well as channel the cement before it sets, the latter condition exists even when the gas volume from the lower formation is too low to be proiitable.

Y With the foregoing problem in view, the objects of our inventionare: y

First, to provide a bridging plug which, when set forms a uid tight seal in the well bore and resists thrust from either above or below.

Second, to provide a bridging plug which may be lowered and positioned by means of a wire rope or cable, particularly a special cable which not only supports the plug but also supplies elec, trical energy thereto.

Third, to provide a bridging plug in which the parts are held in an inoperative position by a rupturable device, which device is adapted to be broken by an explosive cartridge to set the plus.

Fourth, the provide a novel method of setting plugs and the like in well bores which employs an electrically responsive explosive cartridge to release previously set parts, and a current carrying wire rope for supplying. electrical energy 4o to the cartridge.

Fifth, to provide a bridging plug which is so arranged that no great accuracy is required in the fabrication of its elements, these being formed for the most part from castings requiring only a minimum of machining, thereby providing a plug which is particularly economical of manufacture proportional to its functions.

Sixth, to provide a bridging plug wherein most of its elements may be formed from material which'is capable of being drilled up should it be desirable to reopen the zone below the plug, and wherein these elements dene a central bore adapted to, receive cement to facilitate guiding and centering of the drilling bit.

Seventh, to provide a bridging plug wherein the sealing element is disposed at the bottom thereof and the securing means thereabove and is entirely exposed to cement applied on top of the packer whereby the cement entirely surrounds and locks the various parts in their securing positions and forms a completebond appear hereinafter, attention is now directed to the drawings, in which:

Figure 1 is an elevational view of our bridging plug in one form shown suspended from a current carrying wire rope and within a well casing, the parts being shown in their restrained positions.

Figure 2 is an enlarged, partially sectional, partially elevational, view of the bridging plug, taken through 2--2 vof Figure 1 and also with the parts in their restrained positions but with the cable head omitted.

Figure 3 is a sectional view similar to Figure 2 but showing the bridging plug after being set and cement poured thereupon.

Figure 4 is an enlarged fragmentary longitudinally sectional view of the bridging plug taken through 4-4 of Figure 1 and showing the cable head fragmentary and by dotted lines'.

Figure 5 ,is an emerged transverse sectional View of the bridging plug taken through 5-5 of Figure2.

Figure 6 is another emerged transverse sectional view thereof taken through 6-6 of Figure 2.

Figure '7 is another enlarged transverse sectional view thereof taken through 1--1 of Figure 2.

Figure 8 is a reduced elevational view of a bridging plug in its set position and with the cable head omitted.

Figure 10 is a partially elevational, partially sectional view of a further modified form of the bridging plug with the upper portion broken away.

Figure 11 is a transverse sectional view thereof` taken through II-II of Figure 10, and

Figure 12 is a diagrammatical view showing the D manner of ring the plug releasing cartridge.

' The several bridging plug constructions herein illustrated are adapted to be lowered on a. special cable or wire rope I which is similar to the conventional hoisting or haulage rope used in connection with wells and usually referred to as a sand line". The distinction is that in place of the conventional hemp core a special core Ia having a conductor insulated therein is used.

The lower end of the wire rope is connected in any suitable manner to a head structure 2 which has an externally threaded lower end 2a carrying an insulated contact 2b as shown by dotted lines in Fig. 4.

The lower threaded end 2a of the cable head is adapted to receive the internally threaded or socket end 3a of a coupling member 3. Below its socket end, the coupling member is provided with an externally threaded shank 3b which receives the upper end of a sleeve member 4,. In the structure illust ated in Figs. 1 through 7, the

sleeve member is constructed at its lower end to telescope within the upper end of a tubular body member 5, and is secured thereto by rivets 6 or other suitable means which is sufiicient to support the packer or plug from the cable but will readily shear as will be explained in more detail hereinafter.O

The lower end of the coupling member 3 is provided with e threaded breech bleek se which screws into the upper, enlarged part of a release bar 1, below the breech block 3c the release bar is provided with a recess or chamber 1a which receives a cartridge 8. Said cartridge comprises 'a shell 8a. of insulating material lled with an explosive'and having contact means 3b at opposite ends which are connected through the shell and explosive by a fusible wire 8c. Around the cartridge, the release bar 1 is weakened as 5 by an annular groove 1b so that upon ignition of the cartridge the release bar is broken in two.

The coupling 3 is provided with a small bore therethrough which receives an insulated conductor 9 the lower end of which terminates in a head 9a adapted to engage one of the contacts lbwhile the other contact 8b is grounded to the release bar. The upper end oi' the conductor 3 is connected to a suitable terminal means I0 'which engages the contact 2b as shown in Fig- 5 ure 4.

The lower end of the release bar 1 exterds into the body member 5 and terminates in a bifurcated yoke 1c which receives a cross pin II. The extremities of the cross pin protrude through longitudinally extending slots 5a provided in the body member and into suitable holes formed in the lower portion oi.' `a slip setting cone I2. Said cone is in the form of a sleevewhich slides upon the body member and is provided with a irustoconical exterior converging downwardly. The

. lower end of the cone I2 is provided with an annular rib' I2a the upper side of which is undercut.

Above the rib and the pin II, the bore of the cone I2 is enlarged as indicated by I2b and made slightly tapering or truste-conical with its walls converging downwardly. The space thus formed receives a plurality of segmental wedge members I3 which permit downward movement of the cone I2 relative to the body' member but lock against the opposite movem -.t thereof..

y to bear` against the cones.

The upper end of the cone I 2 is further enlarged internally and is threaded to receive a collar I4 which forms a sliding t around the sleeve 4 and body member 5. A spring I5 may be inserted between the collar I4 and wedge members I3 to hold the wedge members in position.

The lower extremity of the body member 5 is externally threaded to receive a plug member I6.

mounted on the body member 5 above the plug member I6. Said cone is similar to the cone I2 but its walls converge upwardly or in opposition" to the cone I2. The lower end of the cone I8 is enlarged internally to t over the constructed upper end of the plug member I6 and is beveled so that when the cone and plug member are moved toward each other the packing sleeve I1 is forced outwardly and against the walls of a surrounding casing as shown in Fig. 3. The upper end of the cone I8 is provided with an annular rib I8a having an undercut lower side.

Between the two cones I2 and I8 the body member 5 receives a pair of ring members I 9. Each ring member has secured thereto a plurality of reins 20 which are provided at their extremities with segmental slips 2|. The ring members are disposed in abutting relation with the reins of the lower slip extending upwardly and those of the upper slip extending downwardly. The slips 2| are provided with tongues 2Ia adjacent their connections with the reins which tongues fit into the undercut sides of the ribs I2a or I 8a. Springs 22 are provided between the ring members and the cones so that the slip assemblies tend to oat between the cones as will be described hereinafter.

In the structure illustrated in Figs. 1 through ,7 a spring is used to expand the packing and set the slips. This spring, designated 23, is attached by one end to the cross pin Il and by its other or lower end to a hook 24a of an anchor screw 24.

Said screw extends through an opening in the lower end of the plug vmember I6 and receives a sealing washer 25 and nut 26. The screw is sufilciently long to provide a means of stretching the spring 23 to the desired tension. The cartridge 8 is ignited by supplying the necessary current as shown diagrammatically in Fig. 12 wherein the cable I is shown as passing over a sheave at the top of the well and around a drum. The conductor is connected through a switch 21 to a source of electrical energy while the cable steel is grounded.

Operation of the bridging plug disclosed in Figures 1 through 7 is as follows:

The parts of the plug occupy the initial positions shown in Figures 1, 2 and 4. The slips are hooked in the undercut sides of the corresponding ribs I2a or Isa and in addition the reins may be formed of spring materiel so that the supe tend The plug member IB and upper cone I2 are secured in relative movement by the sleeve member 4, coupling member 3, releasing bar 1 and cross pin II. When, however, an electrical circuit is completed through the cartridge 8, by closing the switch 21 shown in Figure 12, the releasing bar 1 is broken in two whereupon the spring 23 draws the upper cone I2 downwardly and pulls upwardly on the plug member I6 which forces the lower cone I8 upwardly through the packing sleeve I1. As soon as either 5 the upper or lower set of slips engage the casing wall and are set, the corresponding cone is locked against further movement relative to the casing;

however the other cone is still free to move until the corresponding slips are set. The packing l sleeve I1 even though moving to a sealing position` is still capable of sliding along the casing so that should the sleeve pack oif before the slips set, which is not likely, said slips are still capable of setting. However, in operation the slips tend l to set first so that upon locking of the upper and lower cones relative to the casing the spring ccntinues to exert a force on the packing sleeve tending to expand it into sealing relation with the casing. The wedging members I3 allow the cones and plug member to move toward each other but prevent theA opposite movement thereof so that the `bridging plug cannot work loose once it is set. It should be noted from Figure 3 that the body member 5 does not protrude above the collar I4 .when thebridging plug is set. Therefore should a bailer or other tool engage the bridging plug the force is applied in a manner to further set the slips corresponding to the upper cone. Also pressure from below tends to further set the slips corresponding to the lower cone.

After the bridging plug is set, upward pull on the cable shears the rivets 6 and disconnects the sleeve 4 from the plug so that the cable can be "a withdrawn. The rivets are of such size and material that they are just suiiicient to support the weight of the packer during the interval between breaking the release bar and setting of the packer and are sufficiently 'weak that they will shear before too much load is applied to the cable.

After `setting the plug and withdrawing the cable, cement is poured upon the plug. The cement filters in and around the parts of the plug and forms a complete bond therewith. Once the 40 cement is set, the plug has no vital function although it does relieve the bond between the cement and casing from some of the load in either direction. The primary function of the plug is to provide an adequate and fixed seal in` the casing until the cement is completely set and to ywithstand blows that may be applied from the top as well as formation pressure from below.

Should it be desired to re-enter the well below the plug it is, of course, necessary to drill up the cement and plug. The cement offers no obstacle, and the plug may be constructed for the most part of cast iron or other material-that 'may be readily drilled up. Also, the body member 5 forms a guide for centering the drill.

Attention is now directed to Figures 8 and 9. The bridging plug here illustrated is ingmost respects similar to the first described structure` except that the only one cone and its slips are` used and is primarily intended for use where there is no excessive formation pressure from below. A b'ody member 3l is substituted for the body member i of the first described structure.` In place of the lower cone I8, a ring member 32 is provided which nts over the upper end of the 0 plug member I8 and is beveled at its lower end to expand the packing sleeve I1. Above the. .plug member I6, the ring member 32 is provided with a constructed portion which slides on the body member 3|. One set of reins 20 are attached to the ring I2 and their slips 2| engage the upper after is provided for operating the bridging plug.

To utilize the piston means, the release bar 'lis provided with an integral extension 50 so as toextend beyond the cross bar to the lower extremities of the slots SIb and is adapted toreceive a pistonmember 33 havinga cupped packing ele- `ment'33al arranged in such a manner as to seal against the entrance of fluid into the portion of the body member below the piston. Also the plug member I6 is entirely sealed so as to form with the lower end of the body member and piston a fluid tight chamber. Above the piston and below the slots-IIb, the body member 3| is provided with an internal flange 3Ic which loosely receives the extension 50 of the release bar.

Operation of the second described structure is as follows:

It is customary to maintain a well with a certain quantity of liquid the level of which is usually materially above the point at which it is desired to set the plug, hence there is available a considerable hydrostatic pressure ranging from ve hundred pounds per square inch and materially upward. Inasmuch as the pressure within the chamber, designated A, formed below the piston' 33, remains substantially at atmospheric pressure the hydrostatlcpressure will tend to force the piston toward the bottom of the plug, but is prevented from doing so by the release bar 1 as in the first described structure. When the cartridge is ignited the release bar is broken and thereupon pulls downwardly on the cone I2 and equal force is exerted upwardly on the plug member to seat the slips 2| and expand the packing sleeve I'I. The internal flange 3Ic above the piston restricts the ow of liquid into the space above the piston and thereby tends to retard the setting operation so that the parts will not jam.

l It should be noted that the piston means may be substituted for the spring in the first described structure and vice versa. And also that a loosely tting piston may be associated with the spring to retard its action. The wedge members I3 associated with the cone I2 are particularly useful in conjunction with the second structure shown in Figures 8 and 9 as they prevent .return ofthe cone should the piston leak slightly and equalize the pressure above and below the piston after the plug is set.

Attention is now directed to Figures 10 and 11. Thestructure here illustrated is similar to the rst described structure except that a combined packing and retaining sleeve is substituted for the reins and ring members, and the bottom cone vis incorporated in the plug member. p

The upper cone 4I is identical to cone I2 of the `first structure except that the rib I2a is omitted ties, of the packing sleeve overlie the adjacent' ends of the cones and have vulcanized or otherwise secured thereto a plurality of arcuate clip members 45 which lie against their respective cones. Each slip member includes an anchor portion 45a secured to the packing sleeve and an extended serrated portion 45h protruding 5 beyond the packing sleeve. 'I'he ends of the packing sleeve overlying the anchoring portions 45a are provided with undercut channels forming sealing lips Ma. The sealing lips are disposed radially outward from the serrated or operating portions 45h of the slips and are adapted to compress against the walls of the casing when the cones spread the packing sleeve thereagainst as shown by dotted lines in Figure 10. 'I'his permits the slips to come into engagement with the casing wall and lock the cones only after the packing sleeve has rst made a sealing fit with the casing. Four such sealing ts are made with this arrangement, two operating in each direction. In addition, the central portion of the packing sleeve may be provided with internal sealing lips b which prevent passage of liquid along the body member 42. Only the extreme portions oi the packing sleeve need be stretched; therefore the intermediate portion thereof may be substantially The bridging plug shown in Figs. 10 and 11 may be operated by a spring or by the piston means as shown in conjunction with the iirst two structures.

We claim:

l. A bridging plug comprising: coacting elements adapted to form a binding connection with the walls of a well casing; means tending to actuate said elements; and a device normally restraining said means and incorporating an explosive instrumentality for releasing said means.

2. A bridging plug comprising: coacting elements adapted to form. a bindingconnection with the walls of a well casing; a packing arrangement adapted to form a sealing connection with the walls of the casing; means tending'to actuate said elements and said packing arrangement; a restraining device for said means; and an explosive instrumentality for releasing said means 45 from said restraining device.

3. The combination with a current supplying and supporting cable of a bridging plug comprising: coacting elements adapted to form a binding connection with the walls of a well casing;

50 means tending to actuate said elements; a restraining device for said means; and an explosive instrumentality for .releasing said means from said restraining device.

4. 'I'he combination with an oil well tool adapt- 55 ed to be positioned within a well bore, and a supporting and conducting cable, of a connection means between the cable and tool comprising:

, a frangible connecting member; a cartridge therein 'adapted to rupture the connecting means;

` 00 an electrically responsive igniting means for the cartridge, and means electrically connecting said igniting means with the cable. 5. The combination with an oi-l well tool adapted to be positioned within a well bore, and a sup- 65 porting and conducting cable, of a connection means comprising: a frangible connecting member; a cartridge therein adapted to rupture the frangible connecting member; an electrically responsive igniting means for the cartridge, means 70 electrically connecting said igniting means with the cable, and an auxiliary connecting device also joining the cable and tool arranged to give way upon application of -a predetermined tensional stress therebetween after rupturing of said fran- 75 gible connecting member.

reinforced so as to be relatively non-stretchable.

6. In a bridging plug for wells; a body member; an expanding cone slidably mounted thereon; slips slidably engageable with said cone; yieldable means within the body member tending to shift said cone in a manner to expand the slips against the walls of a surrounding casing; a device for restraining said means; and a remotely actuatable instrumentality for releasing said means from said device.

7. In a bridging plug for wells: a body member; an expanding cone slidably mounted thereon; slips slidably engageable with said cone; means for shifting said cone in a manner to expand the slips against the walls of a surrounding casing; a device for restraining said means; a frangible element incorporated in said device; and an explosive charge positioned so as to rupture said frangble element to release said means from said device.

8. In a bridging plug for wells: a body member; an expanding cone slidably mounted thereon; slips slidably engageable with said cone;

yieldable means within the body member tending to shift said cone in a manner to expand the slips against the walls of a. surrounding casing; a ydevice for restraining said means; a remotely actuatable instrumentality for releasing said means'from said device, and mechanism for securing said cone against a subsequent releasing movement. Y,

9. In an oil well tool of the class described: a packing structure adapted to form a sealing connecting with the walls of a surrounding casi ng; means tending to operate said packing structure; a device restraining said means whereby the packing structure is held in an inoperative condition; and an explosive instrumentality for releasing said means from said. device and cause operation of said packing structure.

10. In an oil well tool of the class described; a packing structure adapted to form a sealing connection with the walls of a surrounding casing; means tending to operate said packing structure; a device restraining said means whereby the packing structure is held in an inoperative condition; an explosive instrumentality for releasing said means from said device and cause operation of said packing structure; and means for securing said packing structure in its operating position.

11. In an oil well tool of the class described;

a bridging plug adapted to engage the walls of a well casing and form a sealing connection therewith; means for restraining said plug in an inoperative condition and connecting said plug with a cable whereby the plug may be lowered and positioned Iin a well casing; and a device for releasing said means, to set said plug and disconnect the cable therefrom, said device including a frangible connecting member and an explosive charge positioned to rupture said connecting member.

l2. The combination with an oil well-tool entity adapted to be lowered into a well bore and having relatively moveable, coacting elements; means tending to urge said elements relatively; and a device restraining said/means, of a releasing mechanism comprising: a frangible member incorporated in said restraining device; an

explosive positioned to break said frangible' member; and means for igniting said explosive.

13. The combination with an oil well tool entity adapted to be lowered into a well bore and having relatively moveable coacting elements.

means tending to urge said elements relatively;

and a device restraining said means of a releasing mechanism comprising: an explosive instrumentality for releasing said means from said device; an electric igniter for said instrumentality; and means for completing an electrical circuit through said igniter.

14. The combination with a bridging plug having relatively movable elements adapted to set the bridging plug within a well bore, and a supporting device for lowering the bridging plug into a Well bore, of a setting and releasing means comprising: a piston and cylinder means responsive to the hydrostatic head of fluid in which the bridging plug is immersed for urging said l5 elements in a manner to set the bridging plug; a restraining and connecting mechanism for withholding action of said piston and cylinder means, and joining said bridging plug to said supporting means; and an instrumentality operable upon said mechanism to release said piston and cylinder means and disconnect said bridging plug from said supporting device.

15. In an oil Well tool: relatively movable elements; a piston and cylinder means associated with said elements to move them relatively vin response to the hydrostatic pressure of well liquid in which the tool is immersed; a rupturable restraining means for said piston and cylinder means; and an explosive instrumentality for rupturing said restraining means to release said piston and cylinder means.

16. In an oil well tool: relatively movable eiements; apiston and cylinder means associated with said elements to move them relatively in response to the hydrostatic pressure of well liquid in which the tool is immersed; a restraining mechanism for said piston and cylinder means for withholding the action thereof; and a device for rendering said restraining means inoperative.

17. The combination with an oil well tool adapted to be lowered into a well bore and a supporting' means therefor, of a connecting means between said tool and supporting means comprising; a frangible connecting member; an explosive cartridge therein adapted to rupture saidv connecting member :'and means for igniting said explosive charge.

18. In an oil well tool: a tool entity adapted to be lowered into a well bore; means for urging operation of said tool entity; an instrumentality for restraining operation of said means including a frangible element; anexplosive charge associated with said element; and means for igniting said explosive charge, said tool entity and urging means adapted to withstand the destructive force of said explosive charge.

WALTER T.WEL1s. CHARLES H. BARNES. -LLoYD SPENCER. 

